Ad libitum

Ad libitum is a Latin expression that literally means 'at pleasure, at will' and it means 'as you like'. It is often abbreviated as ad lib. The expression a bene placito ('to [one's] good pleasure') is roughly synonymous and less common. But in its Italian form a piacere it entered the musical lingua franca. This term, as seen below, is used in different disciplines such as music, biology or politics.

In music

Fragment of the score of the Hungarian Rapsody n.o. 2 by Franz Liszt.

In this field ad libitum is a musical indication meaning "at will" and it can appear in scores and scores. It can have several meanings by noting that the musical performer or conductor has at his disposal a variety of criteria that he can adopt with respect to a given passage:

• to interpret the passage in a free rhythm instead of the strict or "metronomical" tempo. It's the practice known as blond when not expressly indicated by the composer. The alteration affects only the tempos, but never the notes;
• to improvise a melodic line that fits into the general structure established by the notes or chords noted in the passage;
• to omit an instrumental part, as can be an accompaniment that is not essential, for the duration of the passage. In this case is the opposite indication to obliggae;
• when the phrase “repeat” appears ad libitum», to touch the passage of an arbitrary number of times (see ostinato).

On other occasions, it can also appear to indicate that said piece of music can be interpreted with or without the instrument that it indicates. For example, contrabassoon "ad libitum" or "ad lib." (for short).

The indication a piacere has a more restricted meaning, generally referring to only the first two types of criteria. Baroque music, in particular, has a written or implicit ad libitum, whereby most composers hint at the freedom of the performer and conductor. For classical music after the Baroque style and jazz, see cadenza. It was a frequently used resource by Erik Satie.^{[citation needed]}

In other fields

In biology

Ad libitum is also used in psychology and biology to refer to the weight of an animal when no control over its feeding has yet been imposed. An example of this usage might be: "The ad libitum weight of the rat was 320 grams". In nutritional studies, the phrase denotes the free access of an animal to water or food when we let its biological needs regulate consumption. For example: "Rats were provided ad libitum access to food and water."

In field studies of biology it can also mean that the information was obtained spontaneously without a specific method.

In medicine

In the package inserts and clinical research, the abbreviation ad lib. indicates that the administration depends on the will of the patient.

In Catholic liturgy

Ad libitum is used in the Catholic liturgy when referring to a religious festival or free memory of the celebration of a saint from the Catholic saints that can be celebrated or not, at the discretion or discretion of the celebrant or presider of the liturgical celebration.

In politics

Of course it is also used to refer to political decisions that are made "a piacere", that is, focusing on one's own interests instead of those of the voters.

Acting

When reading "ad lib" in a film, theater or television script, it is generally to indicate to the actors that they should improvise, for example, some dialogues.